1. Field for the Invention
The present invention relates to a steering device provided with a tilt-telescopic adjustment function and making it possible to reduce shocks and friction caused by the abutment of parts during the tilt-telescopic adjustment and also noise generated at this time and to obtain good operation feeling.
2. Description of the Related Art
A variety of manual steering devices equipped with a tilt-telescopic adjustment function has been developed and put to practical use. Various means have been used in such devices to reduce shocks, friction, and occurrence of collision noise caused by sliding and abutment of parts during the tilt-telescopic adjustment.
Japanese Patent Application Publication No. 2007-302117 and Japanese Patent Application Publication No. 2004-9796 disclose specific examples of such means. The disclosures of Japanese Patent Application Publication No. 2007-302117 and Japanese Patent Application Publication No. 2004-9796 will be summarized hereinbelow. The explanation below uses the reference numerals used in Japanese Patent Application Publication No. 2007-302117 and Japanese Patent Application Publication No. 2004-9796. In Japanese Patent Application Publication No. 2007-302117, round openings (recesses) (1c) are formed at both ends of a telescopic elongated hole (1b), and a cylindrical buffer member (6) is fitted into the round opening (1c).
The buffer member (6) formed from a rubber or resin has an outer diameter somewhat larger than the inner diameter of the round opening (1c), and after the buffer member has been assembled by press fitting into the round opening (1c), the buffer member is fixedly held inside the round opening (1c) by the elastic force induced by the elastic deformation thereof. With such a configuration, in Japanese Patent Application Publication No. 2007-302117, a clamp bolt (5) collides with the buffer member (6), rather than with the end surface of the telescopic elongated hole (1b), and the shock force is thus relaxed.
In Japanese Patent Application Publication No. 2004-9796, a biasing end portion (folded portion) (22) of a balance or jump-up spring (20) is in contact with a column-side upper bracket (5). During the telescopic adjustment, the biasing end portion (22) slides over the contact zone of the column-side upper bracket (5). A sliding member (30) from a synthetic resin is mounted on the biasing end portion (22) in order to improve sound absorption and sliding characteristics during the sliding.
The sliding member 30 is formed in a substantially U-like shape and has a clip main body portion (31) (accommodation sliding bottom portion), a contact portion (32), and guide portions (33). The clip main body portion (31) expands against its own elastic recovery force (clip force) to accommodate the biasing end portion (22) (folded portion) on the other side of the spring (20). After the biasing end portion (22) has been accommodated in the expanded sliding member (30), the sliding member (30) is compressed by the elastic recovery force (clip force), and holds the biasing end portion (22) (folded portion) of the spring (20). The contact portion (32) with a convex curved surface comes into contact with the column-side bracket (4), and the other biasing end portion (22) (folded portion) of the spring (20) is fixedly attached by the guide portions (33).